Paste JSON to beautify, minify, and validate it — with clear error messages. Nothing leaves your browser.
{
"name": "EngineersUniverse",
"tools": [
"calculators",
"utilities",
"simulators"
],
"free": true,
"toolCount": 230
}This free tool formats, validates, and minifies JSON entirely in your browser using JavaScript's built-in JSON.parse and JSON.stringify. Nothing you paste is ever sent to a server — it's safe to use with sensitive API responses or config files.
API responses and config files are often minified — all on one line with no spacing — to save bandwidth. That makes them nearly unreadable by eye. Beautifying adds consistent indentation and line breaks so nested objects and arrays are easy to scan, without changing the underlying data.
JSON is stricter than JavaScript object syntax. The most frequent validation failures are: a trailing comma after the last item in an object or array (not allowed in JSON), single quotes instead of double quotes, unquoted object keys, and missing commas or closing brackets. This tool reports the exact line and column where parsing failed.
Minifying strips all non-essential whitespace, which reduces payload size for network transfer — useful for production API responses. Formatted (pretty-printed) JSON trades that space efficiency for human readability during development and debugging.
No. All formatting and validation happens locally in your browser. Nothing you paste is transmitted, logged, or stored.
It reformats JSON with consistent indentation so nested structures are easy to read, without changing the underlying data.
Common causes: trailing commas, single quotes instead of double quotes, unquoted keys, or a missing comma/bracket. The error message shows the exact line and column.
JSON requires double-quoted keys and string values, no trailing commas, and no comments or functions — stricter than JavaScript object literal syntax.